Johannes Trithemius (1 February 1462 - 13 December 1516) was an Abbot who was an influential man in his time, being both a historian and a cryptogrpaher, in addition to being a counselor to Emperor Maximilian I. As a cryptogapher he has the distinction of both the first printed work on the subject and he developed a polyalphabetic system based on a "tabula recta." His work Steganographia, had the dubious honor of being placed on the Index Librorum Prohibitorum until the year 1900. Which has lead many people to believe he was an occultist. However, it has been recently shown that this was simply a text book on how to encipher plain text, and was written in a style that prevented people from realizing its purpose due to its bizarre allusions to angels and spirits. That terminology was an intentional obscuration of the method.